Speed Signal Circuit: Procedure

1. Disconnect the H14 combination meter assembly connector.
   Fig 1: H14 Combination Meter Assembly Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   H14-19 (+S) - Body ground	Power switch on (IG)	4.5 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Combination Meter Assembly)

   HINT: 

   If any of the ECUs specified in the wiring diagram supplies power to the combination meter assembly, the combination meter assembly will output a waveform.

NG → See step   5 

OK: Go to next step 

1. Reconnect the H14 combination meter assembly connector.
2. Disconnect the A24 skid control ECU connector.
   Fig 2: A24 Skid Control ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A24-11 (SP1) - Body ground	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Brake Booster with Master Cylinder Assembly (Skid Control ECU))

NG → See step   4 

OK: Go to next step 

1. Check the input waveform.
   Fig 3: H14 & Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Reconnect the A24 skid control ECU connector.
   2. Remove the combination meter assembly with the connector(s) still connected.
   3. Connect an oscilloscope to terminal H14-20 (SI) and body ground.
   4. Turn the power switch on (IG).
   5. Turn the wheel slowly.
   6. Check the signal waveform according to the condition(s) in the table below.

      Item	Condition
      Tool setting	5 V/DIV., 20 ms./DIV.
      Vehicle condition	Wheel being rotated

      TEXT IN ILLUSTRATION
      
      

      *a	Component with harness connected (Combination Meter Assembly)

      OK

      The waveform is similar to that shown in the illustration.

      HINT: 

      When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

NG → See step   16 

OK → See step   17 

1. Disconnect the H14 combination meter assembly connector.
2. Disconnect the A24 skid control ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H14-20 (SI) - A24-11 (SP1)	Always	Below 1 Ω
   H14-20 (SI) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   17 

1. Disconnect the H115 junction connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H14-19 (+S) - H115-20	Always	Below 1 Ω
   H14-19 (+S) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Inspect for a short in the wire harness and connectors connected to the junction connector shown in the wiring diagram.

   HINT: 

   If voltage is not present, it is possible that an ECU or circuit has a malfunction. The malfunctioning ECU or circuit will be diagnosed in the following steps.

   1. Disconnect the H114 and H115 junction connectors.
   2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection	Condition	Specified Condition
      H114-12 - Body ground	Power switch on (IG)	4.5 to 14 V
      H114-13 - Body ground	Power switch on (IG)	4.5 to 14 V
      H114-14 - Body ground	Power switch on (IG)	4.5 to 14 V
      H114-15 - Body ground	Power switch on (IG)	4.5 to 14 V
      H115-19 - Body ground	Power switch on (IG)	4.5 to 14 V
      H115-21 - Body ground	Power switch on (IG)	4.5 to 14 V
      H115-22 - Body ground	Power switch on (IG)	4.5 to 14 V

      Result

      Result	Proceed to
      Voltage is not present in one circuit.	A
      Voltage is present in all of the circuits.	B

B → REPLACE JUNCTION CONNECTOR (INSTRUMENT PANEL WIRE) 

A: Go to next step 

1. Select the circuit for which voltage was not present in step 6.

   Result

   Tester Connection	System that uses the circuit	Proceed to
   H114-12 - Body ground	Vehicle proximity notification system	A
   H114-13 - Body ground	Auto wiper system*1	B
   H114-14 - Body ground	Smart access system with push-button start	C
   H114-15 - Body ground	Audio and visual system*2 or Navigation system*3	D
   H115-19 - Body ground	Automatic headlight beam level control system*4	E
   H115-21 - Body ground	Audio and visual system	E
   H115-22 - Body ground	Safety connect system*5	E

   • *1: w/ Auto wiper system
   • *2: w/o Navigation system
   • *3: w/ Navigation system
   • *4: w/ Automatic headlight beam level control system
   • *5: w/ Manual (SOS) switch

B → See step   9 

C → See step   10 

D → See step   11 

E → See step   12 

A: Go to next step 

1. Disconnect the H50 vehicle approaching speaker controller connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H50-6 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   25 

1. Disconnect the H51 windshield wiper relay assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H51-24 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   24 

1. Disconnect the H1 power management control ECU connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H1-14 (SPDI) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   18 

1. Disconnect the H89*1 or H83*2 radio receiver assembly*3 or H97 multi-media module receiver assembly*4 connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H89-17 (SPD)*1,*3 - Body ground	Always	10 kΩ or higher
   H83-3 (SPD)*2,*3 - Body ground	Always	10 kΩ or higher
   H97-56 (SPD)*4 - Body ground	Always	10 kΩ or higher

   • *1: w/ Multi-display
   • *2: w/o Multi-display
   • *3: for Radio receiver type
   • *4: for Multi-media module receiver type

   Result

   Result	Proceed to
   OK (for Radio receiver type)	A
   OK (for Multi-media module receiver type)	B
   NG	C

B → See step   19 

C → REPAIR OR REPLACE HARNESS OR CONNECTOR 

A → See step   22 

1. Select the circuit for which voltage was not present in step 6.

   Result

   Tester Connection	System that uses the circuit	Proceed to
   H115-19 - Body ground	Automatic headlight beam level control system*1	A
   H115-21 - Body ground	Audio and visual system	B
   H115-22 - Body ground	Safety connect system*2	C

   • *1: w/ Automatic headlight beam level system
   • *2: w/ Manual (SOS) switch

B → See step   14 

C → See step   15 

A: Go to next step 

1. Disconnect the A29 headlight leveling ECU assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A29-16 (SPDR) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   21 

1. Disconnect the H99*1 or H87*2 stereo component amplifier assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H99-17 (SPD)*1 - Body ground	Always	10 kΩ or higher
   H87-11 (SPD)*2 - Body ground	Always	10 kΩ or higher

   • *1: for Multi-media module receiver type
   • *2: for Radio receiver type

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   20 

1. Disconnect the H101 DCM (telematics transceiver) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H101-10 (SPDP) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   23